Apparatus formed from wooden strips and elastic structural adhesive joinery

ABSTRACT

A floor covering apparatus includes at least two elongate wooden strips and an elastic structural adhesive joinery. The adhesive joinery adheres longitudinal adjacent edges of the wooden strips to one another so as to form one or more joints between the wooden strips. Upper surfaces of the wooden strips together define a smooth continuous wooden upper surface of the apparatus. The adhesive joinery is formed from a structural adhesive material that is resilient, elastic, dimensionally dynamic, and mobile. The apparatus is adapted to be installed complete in itself without necessitating the use of fasteners, joinery millwork, or supporting structural securement members.

FIELD OF THE INVENTION

The present invention relates to the field of apparatus formed from wooden strips, and more particularly, to an apparatus formed from wooden strips and elastic structural adhesive joinery.

BACKGROUND OF THE INVENTION

In the prior art, wooden floor coverings (e.g., hardwood floors) and other wooden structures may have been assembled from numerous wood pieces which may have been rigidly held together—and/or permanently secured in their installation locations—by various securing means, such as, for example, joinery, fasteners, adhesives, and supporting structures. Typically, such securing means may have been subject to (a) tremendous dynamic expansion and contraction forces inherent in, and (b) powerfully leveraged forces stemming from impacts and/or other forces incurred during the normal use of, these rigid wooden floor coverings and other structures. Many problems may have resulted from the basic conflict between prior art joinery techniques and the dimensionally dynamic character inherent in wood (e.g., wood expansion, contraction, and warping). In fact, prior art wooden floor coverings and other wooden structures may have tended to be torn, crushed, split, cracked, weakened and/or destroyed over time.

Now, apart from the aforementioned problems with the prior art, in today's world of frequent home and office renovations and improvements, it may be desirable to provide discriminating consumers and end users with a wide selection of flooring options—i.e., beyond mere prior art hardwood floors. Perhaps notably, the prior art has thus far failed to provide for (a) a readily portable floor covering or other structure (b) which is securely formed from a series of adhesively bound parallel wooden strips, (c) without the need for further adhesive or mechanical securement to the subfloor or other supporting structure, and (d) which may still be transported from one location to another in a tight diameter roll. Preferably, such a floor covering would be available having wooden strips with lengths substantially similar to those of prior art (i.e., permanently affixed) hardwood floors.

Unfortunately, none of the adhesives used between the individual wooden elements in prior art floor coverings have thus far been sufficiently strong to enable their use in association with long wooden strips, without necessitating the use of further securing means during installation. For example, many conventionally formed wooden floor coverings—including those disclosed in U.S. Pat. Nos. 2,018,711, 2,045,382, and 2,091,476 to Elmendorf—have utilized adhesives that may have been previously thought to be suitable for use with small wooden tiles and short wooden pieces. For example, the aforementioned Elmendorf patents disclose the preferred use of an industrial latex adhesive rubber compound that, while it may have afforded generally good elastic and adhesion characteristics, had a bond strength of only about 10 pounds per square inch (PSI). Unfortunately, bond strengths in this general order may be suitable for use merely as a temporary adhesive—such as, for example, during transport—but not for continued structural use in an installed configuration. Persons having ordinary skill in the art may have appreciated that such industrial latex adhesive rubber compounds could withstand neither the expansion, contraction and warping forces associated with the use of long wooden strips in floor coverings, nor the normal forces leveraged against these compounds through the ordinary use and loading of the associated wooden floor coverings. That is, persons having ordinary skill in the art will appreciate that some of the prior art (including the aforementioned 1930s Elmendorf patents) discloses structures formed from small wooden tiles that were temporarily held together by adhesives that were suitable only for holding the tiles long enough to permit handling, transport and permanent installation (possibly along with adhesive or mechanical securement) onto a structurally supporting sub-floor.

As aforesaid, persons having ordinary skill in the art may have readily appreciated the shortcomings associated with the prior art. As stated by Professor D. J. Alner in his 1967 book entitled Aspects of Adhesion (at p. 58), that “[prior] to the early 1940s, the rubber-based adhesives industry was mainly concerned with the use of natural rubber either in solution or as a latex; the main application for these adhesives were for surgical tapes and as temporary holding solutions in the motor and footwear industries. With the development of the newer synthetic rubbers and resins it became possible to formulate adhesives having much higher strength”. That is, the use of non-synthetic rubber and resin adhesives from prior to the early 1940s was certainly insufficient to provide any significant substantially permanent structural advantage in association with wooden floor coverings.

The second edition of the Handbook of Adhesives (Von Nostrand Reinhold Co., 1962) sets out the following hierarchy of adhesives (at p. 747) by their structural quality:

“1. Prime structural.

2. Semi-structural.

3. Temporary structural.

4. Secondary structural.

5. Accessory and trim attachment.”

In further describing the last of these categories, the Handbook of Adhesives provides further information concerning the types of adhesives which have heretofore been used in association with floor coverings where it states that “[ . . . ] the least critical of all classifications is accessory and trim attachment. Examples [ . . . include] floor coverings, ceiling materials, [and] ceramic tiles”.

In view of all of the foregoing, it should be appreciated by persons having ordinary skill in the art that prior art floor coverings may typically have utilized adhesives between the individual wooden elements thereof, but that these adhesives were inherently non-structural in nature. It is perhaps, in part, because of the shortcomings associated with these adhesives that persons having ordinary skill in the art have thus far not been equal to the task of developing portable floor coverings that are formed from long parallel wooden strips (i.e., generally analogous to those used in permanently affixed hardwood floors).

Moreover, persons having ordinary skill in the art have thus far failed to appreciate that the use of ‘structural’ adhesives in association with wooden floor coverings may afford a number of advantages, including inter alia those aforesaid. ‘Structural’ adhesives, as defined (at p. 17) in the 1991 edition of The Materials Handbook published by McGraw Hill, are those “adhesives [ . . . ] where bond strength is a critical requirement”. It is perhaps worthwhile to specifically note that non-structural elastic rubber materials are hardly comparable to structural adhesives, which did not originate until after the early 1940s. The preface to the Concise Guide to Structural Adhesives by Werner H. Gutterman (Reinhold Publishing, 1961, at p. V) states that “[from] the modest start in the 1940's when epoxy-based cements first began to show promise as structural or load-bearing adhesives until today when these cements successfully bond the integral parts of strategic bombers, missiles, automobiles and skyscrapers, adhesive research had to keep pace with the constant increasing demands for cements which could meet the varied requirements of a host of new applications.” Therefore, to some extent, the development of structural adhesives has been driven by the demands and requirements of the specific new applications.

Modern structural adhesives—such as urethanes, epoxies and hot melts—typically have bond strengths from 100-200 PSI to more than 1000 PSI. Other structural adhesives may, in the past, have been provided with bond strengths of about 50 PSI or greater. The bond strengths of structural adhesives, therefore, are typically many, many times—and perhaps more than 1 or 2 orders of magnitude greater than—the strength of non-structural accessory and trim attachment adhesives (such as, for example, the industrial latex adhesive rubber compound disclosed in the aforementioned Elmendorf patents).

It should be further appreciated that prior art wooden floor coverings, including those disclosed in the Elemendorf references, lacked the strength to draw and hold substantially-sized wooden adherends into place. As such, prior art wooden floor coverings utilizing adhesives may have been limited to use in association with small wooden ‘tiles’ or pieces of wood, such as those which are disclosed in the Elmendorf references. For example, aforementioned '476 Elmendorf patent states (at page 1, column 2, lines 51-54) that the “only limitation as to the length and width of the tiles is that these dimensions be such as to substantially eliminate warping or distortion of the tiles.” Thus, the prior art has thus far been limited to the use of quite small individual wooden pieces. For example, the '476 Elmendorf reference states (at page 1, column 1, lines 12-21) that the preferred wooden tiles are “not greater than a few inches” in size. Similarly, the aforementioned '382 Elmendorf patent states (at page 1, column 2, lines 46-47) that the preferred wooden pieces are provided in “lengths of [ . . . ] up to several inches”.

In the result, prior art wooden floor coverings have been non-structural in nature (including those disclosed in the Elmendorf references), and were specifically adapted to be, and have relied upon being, securely laid upon a floor (or sub-floor) base, and/or attached to the support of a flexible backing sheet.

What is needed, therefore, is an apparatus that is formed from wooden strips together with an elastic ‘structural’ adhesive joinery. The joinery will preferably be ‘structural’ in nature, so as to provide a general and comprehensive method of wood working that is complete in itself, without the use of fasteners, supporting structures, or joinery millwork. What is also needed is a method of structurally joining long wooden strips together using a structural adhesive.

The prior art has also thus far failed to disclose an aesthetically pleasing and highly functional floor covering formed from long wooden strips that are joined together by an adhesive that extends for at least substantially the entire depth of the individual wooden elements. For example, the aforementioned Elmendorf references disclose:

(a) full depth adhesive joints between the wooden adherends, but without any contact whatsoever between adjacent ones of the wooden pieces—instead with the significant space between the pieces being filled entirely by the non-structural adhesive;

(b) partial depth adhesive joints where the adhesive is exposed and has a thickness less than the wooden pieces, being sunk into the upper or lower face of the floor covering, so as to define a recessed portion; and

(c) partial depth adhesive joints where the adhesive has a thickness less than the wooden pieces, but with shoulder portions of adjacent ones of the wooden pieces touching one another and covering the adhesive joints.

Each of the aforementioned prior art joint structures may be subject to one or more significant problems. For example, the aforementioned '382 Elmendorf patent states (at page 1, column 1, lines 11-20) that one of the problems with the full depth adhesive joints that were provided in the floor covering disclosed in the aforementioned '711 Elmendorf patent was that the “construction causes the sheet to be rather stiff [ . . . such that it] cannot be bent or folded.” Moreover, it was thought that the adhesive joints had to be relatively thin in comparison to the wooden adherends so as to be flexible enough to serve as an efficient hinge (see, for example, page 2, column 1, lines 38-39 of the aforementioned '382 Elmendorf reference). It will, therefore, be appreciated by persons having ordinary skill in the art that full depth adhesive joints have been viewed as undesirable, and generally sought to be avoided, in the prior art.

Additionally—where the prior art adhesive joinery has a thickness less than the wooden pieces and is exposed, being sunk into the upper face of the floor covering, so as to define a recessed portion—dirt and grime may previously have tended to accumulate on, and to be difficult to clean from, the recesses formed by the adhesive at the joints. In fact (at page 1, column 2, lines 7-13 of the '382 reference, and at page 2, column 2, lines 32-36 the '476 reference), Elmendorf teaches that it may be desirable to flip the tiles upside down so that the non-structural adhesive joinery can prevent moisture and foreign matter from entering the recesses.

Any time that adhesive joinery is exposed between adjacent wooden pieces in the floor covering, it may generally tend to create a surface that is neither regular, nor smooth, nor aesthetically appealing to discriminating consumers looking to select a floor covering for use in the homes, etc.

Where the prior art non-structural adhesive joinery is not exposed, but is instead covered by touching wooden shoulders, these shoulders may at times act in much the same manner as a fulcrum. The fulcrum or shoulder may also limit the joint hinge, so that the floor covering might only be bent in one direction, and so as to prevent it from being bent in the other direction. If the joint is bent against the wooden fulcrum, the shoulders would leverage and tear the adhesive bonds that are disclosed in the prior art (including those present in the floor coverings which are disclosed in some of the aforementioned Elmendorf patents). Thus, even when ordinary forces are exerted upon the wooden floor covering during its normal use, the wooden shoulders may tend to exert undue forces on the adhesive thereunder, tending to unduly pry the adhesive apart from the wooden adherends. Additionally, adhesive may seep into the shoulder-to-shoulder contact areas, and later break, tear or peel away from the wooden surface—leading also to an increased risk of ‘tear propagation’ within the adhesive joinery.

What is also needed, therefore, is an apparatus that is formed from wooden strips together with an elastic ‘structural’ adhesive joinery, with the joinery extending for at least substantially the full depth of the wooden strips, and with the wooden strips coming together only at the surface thereof to provide a continuous upper surface that is formed entirely of wood.

It might also be advantageous to provide a wooden floor covering in which, during warping or expansion of an individual wooden element thereof, the adjacent individual wooden elements and an elastic structural adhesive joinery will move along with the warping element (to which they are bound). Preferably, the exertion of stabilizing, bolstering and supporting forces upon the warped, curled, or weakened wooden strip might ultimately draw the warped element back to its original, correct, and unwarped position (such as, for example, when a wooden strip warped or cupped by water dries out and flattens again).

Further, it might be advantageous to provide a wooden floor covering which is portable and can be easily transported and installed by rolling it up into, and/or unrolling it from, a tightly wound standard-sized roll (e.g., a 6, 9 or 12 foot roll) that is well-suited for transport by existing methods (e.g., carpet delivery trucks).

It is an object of this invention to obviate or mitigate one or more of the aforementioned disadvantages and problems which may be associated with the prior art.

SUMMARY OF THE INVENTION

In accordance with the present invention there is disclosed a floor covering apparatus that includes at least two elongate wooden strips and an elastic structural adhesive joinery. The adhesive joinery adheres longitudinal adjacent edges of the wooden strips to one another, so as to form one or more joints between the wooden strips. Upper surfaces of the wooden strips together define a smooth continuous wooden upper surface of the apparatus. The adhesive joinery is formed from a structural adhesive material that is resilient, elastic, dimensionally dynamic, and mobile. The apparatus is adapted to be installed complete in itself without necessitating the use of fasteners, joinery millwork, or supporting structural securement members.

According to an aspect of one preferred embodiment of the invention, the adhesive joinery may preferably extend between the wooden strips for at least substantially the entire thickness of the floor covering apparatus, preferably so as to structurally stabilize both the wooden strips and the continuous wooden upper surface of the apparatus. As such, the wooden strips may preferably, but need not necessarily, be joined, held and drawn together across an entirety of their thickness.

According to an aspect of one preferred embodiment of the invention, the adjacent edges of the wooden strips may preferably be in substantial abutment with one another, preferably so as to structurally stabilize both the wooden strips and the continuous wooden upper surface of the apparatus. Preferably, the substantial abutment occurs only substantially adjacent to the upper surface of the floor covering apparatus.

According to an aspect of one preferred embodiment of the invention, the aforesaid substantial abutment may preferably occur only at the upper surface of the floor covering apparatus. Preferably, the adhesive joinery may extend between the wooden strips for the entire thickness of the floor covering apparatus.

According to an aspect of one preferred embodiment of the invention, each of the adjacent edges of the wooden strips may preferably, but need not necessarily, be beveled so as to define a beveled portion. The adhesive joinery may preferably, but need not necessarily, substantially fill each beveled portion at each of the joints. Each of the wooden strips may preferably, but need not necessarily, be substantially trapezoidal in transverse cross-section, with the lower and upper surfaces of each of the wooden strips being substantially parallel to one another.

According to an aspect of one preferred embodiment of the invention, the joints may preferably, but need not necessarily, exhibit hinge-like flexibility in at least one direction.

According to an aspect of one preferred embodiment of the invention, the wooden strips may preferably, but need not necessarily, be flexibly bound to one another, preferably so as to be adapted for movement substantially freely and independently of one another.

According to an aspect of one preferred embodiment of the invention, impact on and expansion of the wooden strips may preferably, but need not necessarily, resiliently displace the wooden strips, which may preferably, but need not necessarily, tend to be drawn back to their original position, preferably without permanent displacement.

According to an aspect of one preferred embodiment of the invention, the wooden strips may preferably, but need not necessarily, be imprecisely milled, preferably with the joints still being formed as tight joints.

According to an aspect of one preferred embodiment of the invention, expansion forces inherent in the wooden strips and impact forces from use may preferably, but need not necessarily, be dispersed at the joint itself.

According to an aspect of one preferred embodiment of the invention, each of the wooden strips may preferably, but need not necessarily, be a single piece of wood that is preferably more than about 1/50 of an inch in thickness.

According to an aspect of one preferred embodiment of the invention, each single piece of wood may preferably, but need not necessarily, be about ⅛ of an inch in thickness.

According to an aspect of one preferred embodiment of the invention, each of the wooden strips may preferably, but need not necessarily, be a single piece of wood that is preferably more than about 1 foot in length.

According to an aspect of one preferred embodiment of the invention, each single piece of wood may preferably, but need not necessarily, be no more than about 12 feet in length.

According to an aspect of one preferred embodiment of the invention, each single piece of wood may preferably, but need not necessarily, be no more than about 9 feet in length.

According to an aspect of one preferred embodiment of the invention, each single piece of wood may preferably, but need not necessarily, be no more than about 6 feet in length.

According to an aspect of one preferred embodiment of the invention, each of the wooden strips may preferably, but need not necessarily, be a single piece of wood that is preferably more than about ⅛ of an inch in width.

According to an aspect of one preferred embodiment of the invention, each single piece of wood may preferably, but need not necessarily, be between about ⅞ of an inch and about 1 inch in width.

According to an aspect of one preferred embodiment of the invention, the structural adhesive material is a synthetic structural adhesive material that has a bond strength of at least about 50 pounds per square inch (PSI).

According to an aspect of one preferred embodiment of the invention, the structural adhesive material has a bond strength of at least about 100 PSI.

According to an aspect of one preferred embodiment of the invention, the structural adhesive material has a bond strength of at least about 300 PSI.

Thus, the invention obviates and/or mitigates one or more of the aforementioned disadvantages and/or problems which may have been associated with the prior art.

Other advantages, features and characteristics of the present invention, as well as methods of operation and functions of the related elements of the structure, and the combination of parts and economies of manufacture, will become more apparent upon consideration of the following detailed description and the appended claims with reference to the accompanying drawings, the latter of which is briefly described hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features which are believed to be characteristic of the apparatus according to the present invention, as to its structure, organization, use and method of operation, together with further objectives and advantages thereof, will be better understood from the following drawings in which a presently preferred embodiment of the invention will now be illustrated by way of example. It is expressly understood, however, that the drawings are for the purpose of illustration and description only, and are not intended as a definition of the limits of the invention. In the accompanying drawings:

FIG. 1 is a top view of a preferred embodiment of the floor covering apparatus according to the present invention;

FIG. 2 is a longitudinal side view of apparatus shown in FIG. 1; and

FIG. 3 is a transverse side view of the apparatus shown in FIG. 1.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Reference will hereinbelow be made to the drawings. Shown in FIGS. 1 to 3 is a floor covering apparatus 50 according to the present invention. The apparatus 50 (hereinafter, alternately referred to as a panel 50) includes at least two elongate wooden strips 10, 10 and an elastic structural adhesive joinery 20.

The adhesive joinery 20 adheres longitudinal adjacent edges 30 of the wooden strips 10 to one another so as to form one or more joints 22 between the wooden strips 10, 10. Upper surfaces 60 of the wooden strips together define a smooth continuous wooden upper surface 62 of the apparatus 50.

The adhesive joinery 20 preferably extends between the wooden strips 10, 10 for the entire thickness “A” of the floor covering apparatus 50—even at the contacting upper edge 30 surface 60 of the wooden strips 10, by means of a capillary action, porosity, absorbency, and/or fluid loving properties of the wood itself. In this manner, the adhesive joinery 20 preferably structurally stabilizes both the wooden strips 10 and the continuous wooden upper surface 62 of the apparatus 50. As such, the wooden strips 10 are preferably joined, held and drawn together across an entirety of their thickness “A”.

The adjacent edges 30 of the wooden strips 10 are preferably in abutment with one another—even with the adhesive joinery 20 extending the full depth “A” between the pieces 10. That is, the adhesive joinery 20—by a capillary action, porosity, absorbency and/or fluid loving properties of the wood itself—may preferably extend the full depth “A” between the pieces 10, without interfering with the abutment of the wooden strips 10. In this manner, the abutment of the edges 30 preferably structurally stabilizes both the wooden strips 10 and the continuous wooden upper surface 62 of the apparatus 50. Preferably, the abutment occurs only at the upper surface 62 of the floor covering apparatus 50.

Each of the adjacent edges 30 of the wooden strips 10 is preferably beveled so as to define a beveled portion 32. The adhesive joinery 20 preferably fills each beveled portion 32 at each of the joints 22.

Each of the wooden strips 10 is preferably trapezoidal in transverse cross-section, with the lower 64 and upper 60 surfaces of each of the wooden strips 10 being substantially parallel to one another.

The joints 22 preferably exhibit hinge-like flexibility in at least one, and more preferably in two, directions, “D” and “E”.

The adhesive joinery 20 is formed from a synthetic structural adhesive material that is resilient, elastic, dimensionally dynamic, mobile, and has a bond strength of at least about 100 pounds per square inch (PSI).

The wooden strips 10 are preferably flexibly bound to one another. In this manner, the wooden strips 10 are preferably adapted for movement substantially freely and independently of one another.

Impact on, and expansion of, the wooden strips 10 resiliently displaces the wooden strips 10, which preferably tend to be drawn back to their original position, without permanent displacement.

The wooden strips 10 may be imprecisely milled, with the joints 22 still preferably being formed tightly.

Expansion forces inherent in the wooden strips 10 and impact forces from use are preferably dispersed at the joint 22 itself.

Each of the wooden strips 10 is preferably provided as a single piece of wood. Each piece of wood is preferably more than about 1/50 of an inch in thickness “A”. More preferably, each piece of wood may be about ⅛ of an inch in thickness “A”.

Additionally, each piece of wood is preferably more than about 1 foot in length “B”. As well, each piece of wood will preferably be no more than about 12 feet in length “B”. In some contemplated embodiments, each piece of wood may be limited to lengths “B” of no more than about 9 feet or 6 feet.

Further, each piece of wood is preferably more than about ⅛ of an inch in width “C”. In some especially preferred embodiments according to the invention, each piece of wood may more preferably be between about ⅞ of an inch and about 1 inch in width “C”. For example, it is within the scope of the invention to initially provide individual pieces of wood that are nominally 1 inch wide “C”, which pieces might be processed to be in the order of about ⅞ of an inch wide “C”.

The apparatus 50 is adapted to be installed complete in itself without necessitating the use of fasteners, joinery millwork, or supporting structural securement members.

As aforesaid, FIGS. 1 to 3 illustrate a preferred embodiment of the present invention consisting of unmilled strips of wood 10 of equal width “C” and thickness “A”, but of varying and/or random lengths “B” laid side by side. The space between the strips is then filled with resilient elastic dimensionally dynamic joinery adhesive 20.

The resulting panels 50 are sanded and finished with varnish or the like. A prefinished wooden floor panel 50 is produced that is smooth, even and level and has no over-wood catch, no ‘V’ groove, no bevel or micro bevel. The panel 50 is resilient and flexible not rigid, so it can accommodate contours and irregularities in substrates upon which it rests.

Notwithstanding that each panel 50 is adapted to be installed complete in itself without requiring the use of fasteners, etc., multiple prefinished wooden floor panels 50 may be fastened to one another by means of hook and loop fasteners 40 (or an adhesive tape 40 or another adhesive) applied to the bottom of the seam. Then joinery material 20 may be applied to the seam and tooled smooth. In this way a prefinished floor can be installed in any size of room.

Alternately a single large panel 50 may be made that can be rolled up for transport. This may preferably eliminate the need to join panels. For example, the panel 50 may be constructed as a wall-to-wall “carpet-like” tightly rollable structure that is provided in sizes up to about a 12 foot wide rolls, i.e., having a panel rolled width “F” of about 12 feet. Of course, the panel rolled width “F” may alternately be provided in other standard sizes, such as, for example, in 9 foot wide rolls, or in 6 foot wide rolls.

Of course, the fact that the panels 50 may be tightly rolled into standard sized rolls makes them highly portable for transport—whether overseas, across town, or simply from one place in a room to another. This portability allows for an increased flexibility, both in arranging for delivery of the panels 50, and in re-arranging the furniture (along with the portable wooden floor covering panels 50) in a room.

FIG. 3 shows a transverse side view of the invention, wherein a joint 22 profile is shown. The wooden strips 10 contact each other directly at the upper portion 60 of their adjoining edges 30. The joint 22 profile shown ensures that the product 50 of wood joinery has a continuous entirely wooden upper surface 62. In FIG. 3, the chamfer or bevel 32 of the joint 22 profile extends the full thickness “A” of the adjoining and contacting edges 30 of the individual wooden elements 10 such that the chamfered joint edge 32 intersects with the continuous wooden surface 62 provided by the present invention. In FIG. 3, individual wooden elements are indicated by the reference number 10 and their contacting adjacent adjoining edges indicated by the number 30. A continuous entirely wooden surface 62 is illustrated in FIG. 3.

It is perhaps worthwhile to restate that, in the prior art, the durable structural products made of wood have all been assemblies of wooden pieces held rigidly in place by various means. However, this rigidity of construction has pitted joinery, fasteners, adhesives and supporting structures against the tremendous dynamic expansion forces inherent in wood itself, and against powerful leveraged impact forces incurred during the use of various wooden manufacturers. Consequently prior art wooden products have been torn, crushed, split, cracked, weakened and/or destroyed over time.

The present invention eliminates these shortcomings by using a new joinery 20 that is more elastic, resilient, yielding and dimensionally dynamic than the wood 10 it joins (or the overall wooden construction 50). While the joinery 20 of the present invention may be nearly as rigid, strong, hard and unyielding as the tremendous expansion forces of wood itself (as when wood swells due to an increase of its moisture content), it is relatively dynamic, resilient, elastic, and strong enough to yield to these forces and absorb them, rather than allowing the expansion forces to leverage, multiply, telegraph, transfer, find and/or damage the weakest point in the overall wood construction 50. The present joinery 20 maintains structural cohesion and integrity by joining, holding and drawing wooden adherends 10 in place, while also allowing a range of motion (slight or great) relative to tremendous expansion and impact forces inherent in wood.

While the joinery 20 of the present invention need only be somewhat more resilient and elastic and dynamic than the wood 10 itself (or the overall wooden construction 50), it may, if desired, be much more elastic, resilient, and dynamic than that, so as to better serve a particular structural function or application.

Showing how the structurally adhesive mobile wooden joint 22 of the present invention is formed may help to illustrate its structure and/or function. First, the entire depth or thickness “A” of the edges 30 of wooden pieces 10 are bevelled or chamfered 32. Then the wooden pieces 10 are brought into edge-to-edge contact such that a wedge or ‘V’ shaped space 32 is created between them. The wedge or ‘V’ shaped space 32 comes together at, and only at, the surface 60 to form an unbroken continuous upper wooden surface 62. The ‘V’ or wedge shaped space 32 is entirely filled with strong structural resilient, elastic adhesive 20. When the adhesive 20 cures, the panel 50 of the present invention has been formed. If the angle of the wedge shaped joint 22 is widened or narrowed, or if the properties of the structural joinery adhesive 20 are changed, then the joint 22 formed will have different properties.

In short, the elasticity, resilience, strength, flexibility and other properties of the structurally adhesive mobile wooden joinery 20 in the panels 50 of the present invention can be engineered to serve different applications.

The structurally adhesive mobile wooden joinery 20 in the panels 50 of the present invention allow for the construction of a full range of conventional wooden manufactures (and more), without the use of conventional woodworking techniques such as fasteners, joinery millwork, or supporting structures. It joins, holds and draws wooden adherends 10 together, maintaining structural cohesion and integrity, while also allowing a range of motion relative to the tremendous expansion and impact forces inherent in solid wood 10 itself and in wooden manufactures 50.

This is done with an adhesive filled joint 22 between wooden adherends 10 (or pieces of wood) which spans the entire thickness “A” or depth of the joint 22 contact area of the wooden adherends 10, while allowing the wooden pieces to contact each other at, and only at, the edges 30 of their upper surface 60 in order to form a continuous unbroken wooden surface 62 there. While the joinery 20 in the panels 50 of the present invention may be ‘nearly’ as hard, rigid, and unyielding as the wooden pieces 10 joined (or the overall wooden construction 50 formed), it may often be made to be much less rigid. By engineering the joint 22 configuration or the adhesive 20 used, the joinery 20 in the panels 50 of the present invention may be made much more dynamic, elastic, and resilient, than the wood 10 it joins (or the overall wooden construction 50). In this way, the present invention avoids the damage caused by conventional woodworking techniques when rigid, unyielding constructions of conventional wood joinery, fasteners, and/or supporting structures are pitted against tremendous dynamic expansion, and impact forces inherent in wood itself, and in wooden manufactures. I have further described the joint 22 configuration and a preferred embodiment elsewhere herein. Presently, I wish to illustrate the inventive aspects of the present invention by comparison with the prior art of U.S. Pat. Nos. 2,018,711 (Elmendorf), 2,045,382 (Elmendorf), and 2,091,476 (Elmendorf).

The present invention is ‘structural’ in nature as it is a general and comprehensive method of wood working complete in itself without the use of fasteners supporting structures or joinery millwork. Most wooden constructions are ‘structural’ in nature. Secondly, the present invention is called a ‘joinery’ method and wood joinery is ‘structural’ in nature.

The Materials Handbook defines as ‘structural’ those “adhesives . . . where bond strength is a critical requirement”.

Materials Handbook V13, George S. Brady, McGraw Hill, 1991, Pg. 17

Further, a hierarchy of structural quality exists including “(1) Prime Structural; (2) Semi Structural: (3) Temporary Structural; (4) Secondary Structural; and (5) Accessory and Trim Attachment” . . . the least critical of all classifications is accessory and trim attachment. Examples are such as . . . floor coverings, ceiling materials, ceramic tiles”.

Handbook of Adhesives, 2nd Ed., Irving Gheist

Van Nostrand Reinhold, 1962, pg. 747

Thus, the express purpose of the prior art of the aforementioned '382 and '476 Elmendorf patents is to be non-structural then, as it claims for its “objects” to be a “floor covering” installed like “linoleum” (see, for example, the aforementioned '476 Elmendorf patent at lines 1 to 6 of the left column).

Again, Elmendorf compares his invention to “linoleum” in the aforementioned '382 patent (at line 4 of the left column). Further, each one of claims 1 to 5 in the '382 Elmendorf patent describe the invention as being “adapted to be laid on a floor base”. Similarly, the non-structural character of the adhesive and apparatus in Elmendorf's inventions is illustrated by the fact that his tiles are specified to be attached to the support of a “flexible backing sheet” (see, for example, each one of claims 1-7 in the aforementioned '476 patent). In other words, Elmendorf's adhesive tile joint is strictly reliant on the support of a “floor base” or a “backing sheet” in all the claims. Finally, the non-structural character of the aforementioned Elmendorf prior art is evident since his flooring is exclusively described as being laid on the supporting surface of a sub-floor—see, for example, (a) page 1, line 17 of the right column, (b) page 1, line 40 of the right column, (c) page 2, lines 63-68 of the left column, and (d) page 2, lines 10-20 of the right column, of the '382 Elemendorf reference; and (e) page 1, line 33-39 of the left column, and (f) page 2, lines 5, 21, 24 and 41 of the left column, of the '476 Elmendorf patent. Thus, persons having ordinary skill in the art will appreciate that the joinery configuration of the present invention is different in important functional and structural ways (that are both novel and inventive) when compared to the generally non-structural nature of the aforementioned Elmendorf prior art.

The present invention teaches a full depth adhesive joint 22 between wooden adherends 10 which contact at and only at their upper edge 30 to form a continuous entirely wooden upper surface 62. The prior art of Elmendorf is much different. In the aforementioned '711 Elmendorf patent, there is a full depth adhesive joint between the wooden adherends, but the wooden pieces do not contact each other at all. Instead a significant adhesive filled space entirely surrounds the wooden adherends. Subsequently, Elmendorf applied for and was issued the aforementioned '382 patent for the express purpose of avoiding such a full depth adhesive joint between his wooden tiles, which he then perceived to be disadvantageous. Further, the joint configurations of the '382 patent and of the third, more recent, '476 patent are identical—at least in terms of their apparent desire to avoiding anything even approaching a full depth adhesive joint.

Specifically, the prior art states:“ . . . the present invention may be said to have for its object to improve upon the flooring disclosed in that patent [U.S. Pat. No. 2,018,711, wherein . . . ] the elastic compound constitutes a filling extending through the entire thickness of the sheet from one face to the other. This construction causes the sheet to be rather stiff [and it . . . ] cannot be bent or folded [ . . . ]. The object of the present invention is to produce an improved flooring material of the type just described. [ . . . ] In order to attain my aforesaid objects, I employ a grill which is quite thin compared to the thickness of the flooring. [ . . . ] The elements of the grill thus serve as flexible hinge members [ . . . ] simply set or sunk into one face of the sheet or panel” (see page 1, lines 11-53 of the left column of the '382 Elmendorf reference).

In short, while a full depth adhesive joint is a central aspect of the present invention, avoiding a full depth adhesive joint is the stated purpose of the aforementioned '382 and '476 Elmendorf patents. Further, Elmendorf teaches his “adhesive grill” joint as being thin relative to the wooden adherends throughout his patents “thin and flexible enough to serve as an efficient hinge” (see, for example, page 2, lines 38-39 of the left column in the '382 patent).

Elmendorf teaches that “the thin grill structure may be either in the upper or lower face of the sheet” (at page 1, lines 7-8 of the right column of the '382 patent). Similarly, the adhesive grill is described as being only at the upper or the lower face of the flooring in the description of the figures (at page 1, lines 34-39 and 54-55 of the right column in the '382 patent). Relatively thin adhesive grilles are also depicted in the figures themselves. Again the grills are described as being “thin” rather than full depth (at page 1, lines 45-46 of the left column, and at page 2, line 38 of the left column, in the '382 patent). Each one of claims 1-5 in the '382 patent describes elastic filled “recesses” at one face only (top or bottom) of the wooden tiles to accommodate the adhesive. Similarly, in the '476 Elmendorf patent, the description, drawings and claims 4-7 teach and depict his adhesive grill as being thin relative to the thickness of the wooden tiles, and as being located only at the upper or lower face of the wooden tiles—see (a) page 1, lines 6-8 of the right column, and (b) page 2, lines 15-17, lines 34-35, lines 22-23 of the right column, and lines 62-63 of the left column. It is perhaps noteworthy that claims 1-2 of the '476 Elmendorf patent do not claim any adhesive joint or “grill” between the wooden tiles at all. A final proof that the adhesive joint or grill is absolutely not a full depth joint is that Elmendorf discloses that his tiles must be flipped upside down, so that the rubber grill can prevent “moisture” or “foreign matter” from entering (see page 1, lines 7-13 of the right column in the '382 patent, and page 2, lines 32-36 of the right column in the '476 patent).

Importantly, where the aforementioned Elmendorf prior art is provided with a thin adhesive rubber grill, it is also provided with a wooden shoulder or fulcrum down most of the edge depth of its wooden adherends. Here, bare wood contacts bare wood, with no adhesive in between. In contrast, the present invention has a full depth adhesive joint 22 coming together at and only at the surface 62. Consequently, the present invention has no wooden shoulder or fulcrum.

Such a full depth joint 22 maximizes the structural performances of the joint 22 by maximizing the bond surface area and bond strength. More important still, when the adhesive structurally mobile wood joinery 20 of the present invention spans the full depth “A” of the adherends 10, it avoids a bare open wood-to-wood edge contacting shoulder or fulcrum down the depth “A” of the adjoining side edges 30 of the wooden adherends 10 as in the prior art. In this way, the present invention may avoid several problems associated with the prior art.

In the prior art, such a side of edge wood-to-wood contact installs a wooden shoulder or fulcrum within the joint. This fulcrum or shoulder limits the joints to being bent or hinged only in the forward direction, while also preventing it from being bent or hinged in the backward direction in the prior art. If the joint is bent or hinged backward, the wooden shoulder or fulcrum would leverage and tear the adhesive bond in the aforementioned Elmendorf prior art.

Further, if a wooden shoulder or fulcrum exists between the wooden adherends, some of the joinery adhesive will invariably seep in places into the wood-to-wood contact area of the shoulder or fulcrum. Then, when the joint is bent or hinged even slightly, the adhesive will break or tear at the wood-to-wood edge contact area of the shoulder or fulcrum of the wooden adherends. This initial tear can lead to adhesive ‘peel’, where the joinery adhesive bonds to the wooden surface of the adherends, and also to ‘tear propagation’ within the adhesive joinery material itself.

In addition to avoiding some or all of these problems, the fact that the present invention has a full depth adhesive joint 22 contacting at and only at the upper edge 30 of the wooden adherends 10 prevents moisture or foreign matter from entering into the joint 22. However, in the case of the aforementioned Elmendorf prior art, this problem of moisture and foreign matter is, more laboriously and less satisfactorily, addressed by flipping the tile upside down, and exposing a significant width of unsightly, and perhaps unserviceable, adhesive filled space between the wooden tiles (see, for example, page 1, lines 7-13 of the right column in the '382 Elmendorf patent, and page 2, lines 32-36 of the right column in the '476 Elmendorf patent).

Finally, the full depth adhesive joint 22 of the present invention joins, holds and draws the wooden pieces 10 together with joinery 20 material applied to the entire thickness “A” of the edge 30 of each wooden piece 10. This means that, if expansion forces attempt to cup or curl the individual wooden pieces 10 in the present invention, structural cohesion and integrity will be maintained and stabilized generally, and especially at the surface 62. The wooden adherends 10 will tend be stabilized at the surface 62, and down the entire thickness “A” of their edges 30, by their adhesive attachment at the surface 62 and down the entire depth “A” of their edges 30 to the adjacent wooden piece 10. If the expansion force of the wood is great enough, the edge 30 of the strip 10 may move or curl or warp somewhat, but the edge 30 of the adjacent wooden adhered 10 and the joinery 20 compound will move with it—stabilizing, bolstering and lending support to the warped, curled, weakened wooden strip 10 while ultimately drawing it back to its original correct, unwarped position (such as, for example, when a wooden strip 10 warped or cupped by water dries out and flattens again).

In contrast, the aforementioned Elmendorf prior art is limited to “tiles [or . . . ] blocks [rather] than long boards to reduce to a minimum the likelihood of warping these tiles [ . . . ] ordinarily [ . . . ] will not be [ . . . ] greater than a few inches [long]” (at page 1, lines 13-21 of the left column in the '476 Elmendorf patent), and again, Elmendorf specifies that the tiles “preferably have edge lengths from one inch up to several inches” (page 1, lines 46-47 of the right column in the '382 patent). In other words, the aforementioned Elmendorf prior art is reliant on the small size of wooden tiles, rather than upon any structural property of his teachings for the stability and functionality of his flooring.

An embodiment of the present invention illustrates the preceding points. In the present invention, a kitchen cutting board may be well made of wood strips 10 only ⅛ of an inch thick “A”. Such an embodiment would have a relatively minimal likelihood of splitting, especially in comparison to a much thicker, conventionally made, cutting board. Rather, in the cutting board made according to the present invention, the wooden surface 62 would remain intact and stable against moisture and food grime.

In contrast, a cutting board made in accordance with the aforementioned Elmendorf prior art would admit substantially more moisture and food grime into the bare wooden shoulder or fulcrum that he teaches. Then, the cutting board made in accordance with the aforementioned Elmendorf references would warp and curl badly as the adherends would not be held and drawn into their correct positions against warping and expansion forces, and the relatively unsupported wooden adherends would be prone to split and break up.

The elastic industrial latex adhesive rubber compound Elmendorf specified as the preferred material in his 1930s inventions may be known to have generally good adhesion and elasticity characteristics, but it may have a bond strength of only about 10 pounds per square inch (PSI). This characteristic provides further evidence that the material is definitely a non-structural elastic rubber material, and it is hardly comparable to structural adhesives, which only originated in the 1940s (i.e., well after Elmendorf's inventions).

The following technical references illustrate the point that the adhesive, natural rubber latex liquid compounds specified in the prior art were non-structural temporary holding solutions. These were suited, as described in the prior art to temporarily holding laid-up sheets or panels of wooden parquet tiles together long enough for handling, transport and/or permanent installation onto a structurally supporting sub-floor.

“Prior to the early 1940's, the rubber-based adhesives industry was mainly concerned with the use of natural rubber either in solution or as a latex; the main application for these adhesives were for surgical tapes and as temporary holding solutions in the motor and footwear industries. With the development of the newer synthetic rubbers and resins it became possible to formulate adhesives having much higher strength, and consequently permitted the elimination of mechanical attachment for a number of applications.”

Aspects of Adhesion—3

Professor, D. J. Alner, pg. 58, University of London Press, 1967

The following technical citation corroborates the prior one in dating the advent of structural adhesives to the 1940s, and suggests commercialization of those materials began in the 1950s.

“Preface . . .

“With the tremendous increase in the manufacturer and uses of structural adhesives, there has developed a definite need for a reference working surveying this field. The fact that only a few years ago such a publication could not have listed a sufficient number of adhesives and manufacturers to justify its appearance, testifies to the rapidity with which the structural adhesives industry has expanded and diversified its products.

“From the modest start in the 1940's when epoxy-based cements first began to show promise as structural or load-bearing adhesives until today when these cements successfully bond the integral parts of strategic bombers, missiles, automobiles and skyscrapers, adhesive research had to keep pace with the constant increasing demands for cements which could meet the varied requirements of a host of new applications.”

Concise Guide to Structural Adhesives

Werner H. Gutterman, Reinhold Publishing, 1961, Pg. V

These modern structural adhesives such as urethanes, epoxies and hot melts, have bond strengths from one or two hundred PSI to more than one thousand PSI. This is many, many times the strength of the elastic rubber latex adhesive compound that Elmendorf specifies. Unlike the present invention, Elmendorf's invention lacks the strength to hold and draw wooden adherends into place, and this fact limits his invention to ‘tiles’ of small pieces of wood. “The only limitation as to the length and width of the tiles is that these dimensions be such as to substantially eliminate warping or distortion of the tiles” (at page 1, lines 51-54 of the right column in the '476 Elmendorf reference). Thus, small wood size is relied upon, rather than structural adhesive strength, to stabilize Elmendorf's tiles of “not greater than a few inches” as larger pieces of wood would “warp” (see, for example, page 1, line 12-21 of the left column in the '476 patent). Again, Elmendorf notes that his tiles are preferably provided in “lengths of [ . . . ] up to several inches” (at page 1, line 46-47 of the right column in the '382 patent). The non structural elastic, rubber, latex adhesive that Elmendorf specifies strictly limits his invention to laid-up sheets or panels of parquet flooring tiles for the sole purpose of facilitating transport handling and installation upon a sub-floor. Elmendorf uses the term “tiles” thirty-five (35) times in the specification and claims of the '382 patent, and the term “tiles” is used sixty-five (65) times in the specification and claims of the '476 patent.

All of the figures in the aforementioned Elmendorf references depict tiles. In addition, all but one of the claims recite “tiles”. In the sole exception, claim 3 of the '382 patent recites “pieces of wood” instead of “tiles”, but the pieces of wood are, as discussed earlier, limited to a few inches in length in both of the aforementioned Elmendorf patents.

In forming one preferred embodiment of the invention, wooden strips 10 of about nine feet long were used. A bevel or chamfer 32 of about fifteen (15) degrees was cut into the full edge 30 thickness “A” of each strip 10. The strips 10 were brought into edge-to-edge contact forming ‘V’ or wedge shaped spaces 32 of about thirty (30) degrees over the full thickness “A” of the wooden strips 10. The ‘V’ or wedge shaped spaces 32 were filled with a structural, elastomeric adhesive 20 compound having about two hundred (200) PSI of bond strength.

An unsupported, rollable, portable entirely wooden surface 62 was formed having an area of 9 feet by 9 feet. The panels so formed 50 might serve as a partition wall, a portable dance floor, or a pre-aid floor installation similar in appearance to conventional plank flooring. The surface 62 might be waterproof, and squeak-free and would have structural integrity independent of being bonded or fastened to any sub-floor supporting surface or backing sheet.

The present invention of structurally adhesive mobile wood joinery 20 in panels 50 constitutes a comprehensive means of woodworking in general. It joins, holds and draws wooden pieces 10 together—maintaining structural cohesion and integrity, while allowing, during installed use, a range of motion (however slight) in order to absorb tremendous expansion and impact forces inherent in the wooden pieces 10 themselves and in a given wooden manufacture 50. It does this by means of an adhesive joint 22 which spans the entire edge depth or thickness “A” of wooden adherends 10 or pieces, while allowing the wooden pieces 10 to come together in wood-to-wood contact at and only at their upper surface 60 to form a continuous entirely wooden upper surface 62. The joints 22 formed need only be slightly more dynamic resilient and elastic than the wooden pieces 10 they join (or the overall wooden construction 50).

In other words the joinery 20 in the panels 50 formed may appear to be fairly hard and rigid. Alternately, however, the joint 22 formed may be engineered to be substantially more dynamic, resilient and elastic. This is done by increasing the width or narrowness of the ‘V’ or wedge shaped 32 adhesive joint 22 and/or by varying the joinery 20 compound used and/or by changing the joinery 20 configuration in other ways.

Other modifications and alterations may be used in the design and manufacture of other embodiments according to the present invention without departing from the spirit and scope of the invention, which is limited only by the accompanying claims. 

1. A floor covering apparatus comprising at least two elongate wooden strips and an elastic structural adhesive joinery, wherein the adhesive joinery adheres longitudinal adjacent edges of the wooden strips to one another so as to form one or more joints between the wooden strips, wherein upper surfaces of the wooden strips together define a smooth continuous wooden upper surface of the apparatus, wherein the adhesive joinery is formed from a structural adhesive material that is resilient, elastic, dimensionally dynamic, and mobile, and wherein the apparatus is adapted to be installed complete in itself without necessitating the use of fasteners, joinery millwork, or supporting structural securement members.
 2. The apparatus of claim 1, wherein the adhesive joinery extends between the wooden strips for at least substantially the entire thickness of the floor covering apparatus, so as to structurally stabilize both the wooden strips and the continuous wooden upper surface of the apparatus, and such that the wooden strips are joined, held and drawn together across an entirety of their thickness.
 3. The apparatus of claim 2, wherein the adjacent edges of the wooden strips are in substantial abutment with one another, so as to structurally stabilize both the wooden strips and the continuous wooden upper surface of the apparatus, and wherein the aforesaid substantial abutment occurs only substantially adjacent to the upper surface of the floor covering apparatus.
 4. The apparatus of claim 3, wherein the aforesaid substantial abutment occurs only at the upper surface of the floor covering apparatus, and wherein the adhesive joinery extends between the wooden strips for the entire thickness of the floor covering apparatus.
 5. The apparatus of claim 3, wherein each of the adjacent edges of the wooden strips is beveled so as to define a beveled portion, wherein the adhesive joinery substantially fills each beveled portion at each of the joints, and wherein each of the wooden strips is substantially trapezoidal in transverse cross-section, with the lower and upper surfaces of each of the wooden strips being substantially parallel to one another.
 6. The apparatus of claim 3, wherein the joints exhibit hinge-like flexibility in at least one direction.
 7. The apparatus of claim 6, wherein the wooden strips are flexibly bound to one another, so as to be adapted for movement substantially freely and independently of one another.
 8. The apparatus of claim 7, wherein impact on and expansion of the wooden strips resiliently displaces the wooden strips, which tend to be drawn back to their original position, without permanent displacement.
 9. The apparatus of claim 8, wherein the wooden strips are imprecisely milled, with the joints still being formed as tight joints.
 10. The apparatus of claim 9, wherein expansion forces inherent in the wooden strips and impact forces from use are dispersed at the joint itself.
 11. The apparatus of claim 1, wherein each of the wooden strips is a single piece of wood that is more than about 1/50 of an inch in thickness.
 12. The apparatus of claim 11, wherein each single piece of wood is about ⅛ of an inch in thickness.
 13. The apparatus of claim 1, wherein each of the wooden strips is a single piece of wood that is more than about 1 foot in length.
 14. The apparatus of claim 13, wherein each single piece of wood is no more than about 12 feet in length.
 15. The apparatus of claim 14, wherein each single piece of wood is no more than about 9 feet in length.
 16. The apparatus of claim 15, wherein each single piece of wood is no more than about 6 feet in length.
 17. The apparatus of claim 1, wherein each of the wooden strips is a single piece of wood that is more than about ⅛ of an inch in width.
 18. The apparatus of claim 17, wherein each single piece of wood is between about ⅞ of an inch and about 1 inch in width.
 19. The apparatus of claim 1, wherein the structural adhesive material is a synthetic structural adhesive material that has a bond strength of at least about 50 pounds per square inch (PSI).
 20. The apparatus of claim 19, wherein the synthetic structural adhesive material has a bond strength of at least about 100 PSI.
 21. The apparatus of claim 20, wherein the synthetic structural adhesive material has a bond strength of at least about 300 PSI. 